Maths and English questions from the entrance examinations for the prestigious Kyoto University were placed on Yahoo! Japan`s question-and-answer service web page on Friday and Saturday.
The postings were made under the same user name, "aicezuki", which does not seem to relate to any common Japanese term, and online answers were soon offered for his or her appeal.
A Kyoto University official confirmed that the postings matched questions from their tests.
Other top institutions, including the private Waseda and Keio universities, faced similar problems, Japanese media reported Sunday as the Kyoto incident made front-page headlines.
The top-selling Yomiuri Shimbun suspected that candidates took pictures of questions on their mobile phones and sent them to an outside associate who placed the queries online.
Other media suggested that pranksters might have been trying to show off their abilities under tight security and supervision at the test sites.
Japanese college exams are the culmination of the country`s intensive school education system and a highly emotional and stressful time for those who take part.
Entrance to elite Japanese universities -- which for decades has been effectively a virtual guarantee of a well-paid job after graduation -- is based largely on the results.
Cheating in the tests is believed to be rare but not unprecedented, with users of other methods, such as paying substitutes to take the test, caught in the past.
The schools were embarrassed by the latest disclosures.
"Our institution has started an investigation over the facts of the matter.
We shall take strict actions if we discover wrongdoings," said Toshiyuki Awaji, a science professor at Kyoto and director-general of its Institute for the Promotion of Excellence in Higher Education.
"We ask test applicants to remain calm despite this," he said in a statement.
Doshisha University, another elite private university affected by the scandal, said in a statement: "We shall investigate facts of the matter. If wrongful acts are confirmed, we shall sternly deal with them."(*)
Editor: Ruslan Burhani
Copyright © ANTARA 2011
